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Vanadium redox flow battery is a new type of battery has many advantages compared to more traditional batteries . However, the development of the vanadium battery is also subject to certain restrictions , mainly three factors : the electrode material , separator and electrolyte . Vanadium battery electrode material must have the following characteristics : good stability ; good mechanical properties , acid resistance , anti pentavalent vanadium strong oxidizing to extend battery life ; electrochemical activity to ensure that the Vanadium electrode the reaction proceeds, and causes the deposition potential of hydrogen and oxygen reaches a minimum ; good conductivity; costs as low as possible . Far , the domestic use of the electrode material is graphite felt class . Graphite felt surface is hydrophobic , poor electrochemical activity , electrode reaction reversibility poor , the pair of electrodes need to select the appropriate method for surface modification, the graphite felt the effective surface area is increased , the mat surface -CO,-C = O an increase in the oxygen - containing functional groups , the reaction of the activation of the vanadium battery system , acceleration passed vanadium ions , and to reduce the reaction of the vanadium ions in the graphite felt electrode overpotential . This thesis using sulfuric acid , Prussian blue , electrochemical anodic oxidation method modified graphite felt electrode material , graphite felt as a the vanadium battery electrode materials cyclic voltammetry compare before and after modification ; experiment by charging and discharging the battery energy efficiency , voltage efficiency compared before and after modification the , coulomb efficiency changes , graphite felt surface resistivity changes and changes in the charging voltage and the discharge voltage ; by potentiometric titration quantitative analysis modified graphite felt , the amount of increase in the oxygen - containing functional groups , thus demonstrating that modified graphite felt as the electrode material can be activated the electrode reaction of the vanadium battery , vanadium ions accelerated passed , reduce the reaction of the vanadium ions in the graphite felt electrode overpotential graphite felt ; finally through a scanning electron microscope before and after modification of the surface morphology .
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